Three classes of resonant tunneling transistors have been constructed and/or proposed in the literature. Examples of these structures are: a resonant tunneling emitter transistor; a hot electron transistor; and a quantum well resonant tunneling base transistor. Each of these structures uses the alignment of quantized energy levels in the conduction band of the quantum well to achieve negative differential resistance. The major problem is that all of these structures have a low peak-to-valley current ratio and are mostly functional at low temperatures. Further, it is difficult to contact theses structures (e.g. base, emitter, collector or gate, source, drain) without incurring unacceptable amounts of leakage current between contacts.
Accordingly, a resonant tunneling transistor with increased peak-to-valley current and reduced contact leakage current is highly desirable.
It is a purpose of the present invention to provide a new and improved band-to-band resonant tunneling transistor.
It is another purpose of the present invention to provide a new and improved band-to-band resonant tunneling transistor with substantially increased peak-to-valley current.
It is still another purpose of the present invention to provide a new and improved band-to-band resonant tunneling transistor with minimized intercontact leakage current.
It is yet another purpose of the present invention to provide a new and improved band-to-band resonant tunneling transistor with substantially reduced access resistance.